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Electronic central monitoring system, called Remote Monitor Alarm System, RMAS, used to monitor malfunction alarms and power supplies of remotely located equipment modules of transmitting and receiving equipment in fiber-optic communication network at Kennedy Space Center. Includes central monitoring unit at location convenient for technicians, plus remote terminal unit at each remote site containing equipment to be monitored.
The goal of the mathematical and statistical analysis component of RICIS is to research, develop, and evaluate mathematical and statistical techniques for aerospace technology applications. Specific research areas of interest include modeling, simulation, experiment design, reliability assessment, and numerical analysis.
We report on measurements of the angular stability, commonly called 'jitter', of the STS Orbiter during normal operations in space. Measurements were carried out by measuring optically the Orbiter's roll and pitch orientation relative to the solar vector as the orbiter was held in a -Z(sub 0) solar inertial orientation (orbiter bay oriented toward the Sun). We also report observations of an interesting perturbation to the orbiter's orientation noted by the crew during the STS-60 mission. These data may be useful in analyzing the in-orbit response of the Orbiter to thruster firings and other applied torques, and may aid in the planning of future experiments that require fine-pointed operations by the orbiter.
Scheduling has become an increasingly important element in today's society and workplace. Within the NASA environment, scheduling is one of the most frequently performed and challenging functions. Towards meeting NASA's scheduling needs, a research version of a generic expert scheduling system architecture and toolkit has been developed. This final report describes the development and testing of GUESS (Generically Used Expert Scheduling System).
System of multimode fiber-optic communication links upgraded to enable simultaneous communication on two channels in each fiber. Incorporates two-wavelength-division multiplexing at both ends of each fiber so two signals transmitted, either in same direction or in opposite directions.
This report documents the fourth Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Intercalibration Round-Robin Experiment (SIRREX-4), which was held at the National Institute of Standards and Technology (NIST) on 3-10 May 1995. The agenda for SIRREX-4 was established by a consensus reached at the conclusion of SIRREX-3: there should be an emphasis on training and work to foster and encourage uniform use of accepted protocols for calibrating radiometric instruments in the laboratory. The goal was to host the activity in a setting where proper techniques could be discussed and demonstrated. It seemed appealing to split the day between morning lectures and afternoon laboratory exercises or practicals. The former gave the user community a chance to present what was important to them and discuss it with acknowledged experts in radiometry, while the latter presented a unique opportunity for training and evaluation in the presence of these same experts. The five laboratory sessions were concerned with (1) determining the responsivity of a spectroradiometer and the spectral radiance of an unknown integrating sphere source, (2) demonstrating spectral field calibration procedures for an integrating sphere using three different instruments, (3) measuring spectral radiance using the plaque method, (4) setting up and aligning lamp calibration transfer standards using the NIST specifications for irradiance measurements, and (5) characterizing radiometric instruments. In addition to documenting some supplemental studies performed outside the laboratory sessions, this report includes an evaluation of the hardware that has been used during the SIRREX activities plus a critical evaluation of SIRREX objectives.
A remote monitor alarm system monitors discrete alarm and analog power supply voltage conditions at remotely located communications terminal equipment. A central monitoring unit (CMU) is connected via serial data links to each of a plurality of remote terminal units (RTUS) that monitor the alarm and power supply conditions of the remote terminal equipment. Each RTU can monitor and store condition information of both discrete alarm points and analog power supply voltage points in its associated communications terminal equipment. The stored alarm information is periodically transmitted to the CMU in response to sequential polling of the RTUS. The number of monitored alarm inputs and permissible voltage ranges for the analog inputs can be remotely configured at the CMU and downloaded into programmable memory at each RTU. The CMU includes a video display, a hard disk memory, a line printer and an audio alarm for communicating and storing the alarm information received from each RTU.
The sea surface directional wave spectrum was measured for the first time in all quadrants of a hurricane in open water using the NASA airborne scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane hunter aircraft at 1.5 km height. The SRA measures the energetic portion of the directional wave spectrum by generating a topographic map of the sea surface. At 8 Hz, the SRA sweeps a radar beam of 1' half-power width (two-way) across the aircraft ground track over a swath equal to 0.8 of the aircraft height, simultaneously measuring the backscattered power at its 36 GHz (8.3 mm) operating frequency and the range to the sea surface at 64 positions. These slant ranges are multiplied by the cosine of the off-nadir angles to determine the vertical distances from the aircraft to the sea surface. Subtracting these distances from the aircraft height produces the sea surface elevation map. The sea surface topography is interpolated to a uniform grid, transformed by a two dimensional FFT, and Doppler corrected. The open-ocean data were acquired on 24 August 1998 when hurricane Bonnie was east of the Bahamas and moving toward 330 deg at about 5 m/s. Individual waves up to 18 m height were observed and the spatial variation of the wave field was dramatic. The dominant waves generally propagated at significant angles to the downwind direction. At some positions there were three different wave fields of comparable energy crossing each other. The NOAA aircraft spent over five hours within 180 km of the eye, and made five eye penetrations. On 26 August 1998, the NOAA aircraft flew at 2.2 km height when hurricane Bonnie was making landfall near Wilmington, NC, documenting the directional wave spectrum in the region between Charleston, SC and Cape Hatteras, NC. The aircraft flight lines included segments near and along the shoreline as well as far offshore. Animations of the directional wave spectrum spatial variation along the aircraft tracks on the two flights will be presented using a 100: 1 time compression.
Because communities are impacted by steady increases in aircraft traffic, aircraft noise continues to be a growing problem for the growth of commercial aviation. Research has focused on improving the design of specific high noise source areas of aircraft and on noise control measures to alleviate noise radiated from aircraft to the surrounding environment. Engine duct liners have long been a principal means of attenuating engine noise. The ability to control in-situ the acoustic impedance of a liner would provide a valuable tool to improve the performance of liners. The acoustic impedance of a liner is directly related to the sound absorption qualities of that liner. Increased attenuation rates, the ability to change liner acoustic impedance to match various operating conditions, or the ability to tune a liner to more precisely match design impedance represent some ways that in-situ impedance control could be useful. With this in mind, the research to be investigated will focus on improvements in the ability to control liner impedance using a mean flow through the liner which is referred to as bias flow.
On 26 August 1998, hurricane Bonnie was making landfall near Wilmington, NC. The NASA airborne scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane hunter aircraft at 2.2 km height documented the sea surface directional wave spectrum in the region between Charleston, SC and Cape Hatteras, NC. The aircraft ground track included both segments along the shoreline and Pamlico Sound as well as far offshore. An animation of the directional wave spectrum spatial variation at landfall will be presented and contrasted with the spatial variation when Bonnie was in the open ocean on 24 August 1998.
The sea surface directional wave spectrum was measured for the first time in all quadrants of a hurricane in open water using the NASA airborne scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane hunter aircraft at 1.5 km height. The SRA measures the energetic portion of the directional wave spectrum by generating a topographic map of the sea surface. At 8 Hz, the SRA sweeps a radar beam of 1 E half-power width (two-way) across the aircraft ground track over a swath equal to 0.8 of the aircraft height, simultaneously measuring the backscattered power at its 36 GHz (8.3 mm) operating frequency and the range to the sea surface at 64 positions. These slant ranges are multiplied by the cosine of the incidence angles to determine the vertical distances from the aircraft to the sea surface. Subtracting these distances from the aircraft height produces the sea surface elevation map. The sea surface topography is interpolated to a uniform grid, transformed by a two-dimensional FFT, and Doppler corrected. The open-ocean data were acquired on 24 August 1998 when hurricane Bonnie was east of the Bahamas and moving slowly to the north. Individual waves with heights up to 18 m were observed and the spatial variation of the wave field was dramatic. The dominant waves generally propagated at significant angles to the downwind direction. At some positions there were three different wave fields of comparable energy crossing each other. The NOAA aircraft spent over five hours within 180 km of the hurricane Bonnie eye, and made five eye penetrations. A 3-minute animation of the directional wave spectrum spatial variation over this period will be shown as well as summary plots of the wave field spatial variation. On 26 August 1998, the NOAA aircraft flew at 2.2 km height when hurricane Bonnie was making landfall near Wilmington, NC, documenting the directional wave spectrum in the region between Charleston, SC and Cape Hatteras, NC. The aircraft ground track included both segments along the shoreline and Pamlico Sound as well as far offshore. An animation of the directional wave spectrum spatial variation at landfall will be presented and contrasted with the spatial variation when Bonnie was in the open ocean on 24 August 1998.
On 26 August 1998, the NASA Scanning Radar Altimeter (SRA) flew aboard one of the WP-3D hurricane research aircraft to document the sea surface directional wave spectrum in the region between Charleston, SC and Cape Hatteras, NC, as Bonnie, a large Category 3 hurricane, was making landfall near Wilmington, NC. Two days earlier, the SRA had documented the wave field spatial variation in open water when Hurricane Bonnie was 400 km east of Abaco Island, Bahamas. Bonnie was similar in size during the two flights, but the maximum speed in the NOAA Hurricane Research Division surface wind analysis was 15% lower prior to landfall (39 m/s) than it had been in the open ocean (46 m/s). This was compensated for by its faster movement prior to landfall (9.5 m/s) than when it was encountered in the open ocean (5 m/s). The slower movement matched the group velocity of waves of 65 m length, so waves at the peak of the spectrum outdistanced the storm as soon as they were generated. The higher translation speed prior to landfall matched the group velocity of waves of 230 m length, significantly increasing the effective fetch and duration of waves near the peak of the spectrum which propagated in the direction of the storm track. The open ocean wave height variation indicated that Hurricane Bonnie would have produced waves of 11 m significant wave height on the shore northeast of Wilmington had it not been for the continental shelf. The bathymetry distributed the steepening and breaking process across the shelf so that the wavelength and wave height were reduced gradually as the shore was approached. The wave height 5 km from shore was about 4 m.
On 26 August 1998, the SRA at 2.2 km height documented the directional wave spectrum in the region between Charleston, SC, and Cape Hatteras, NC, as Hurricane Bonnie was making landfall near Wilmington, NC. The storm was similar in size during the two flights, but the maximum speed in the NOAA Hurricane Research Division surface wind analysis was 15% lower prior to landfall (39 m/s) than it had been in the open ocean (46 m/s). This was compensated for by its faster movement prior to landfall (9.5 m/s) than when it was encountered in the open ocean (5 m/s), significantly increasing the effective fetch and duration of waves near the peak of the spectrum which propagated in the direction of the storm track. The open ocean wave height variation indicated that Hurricane Bonnie would have produced waves of 11 m significant wave height on the shore northeast of Wilmington had it not been for the continental shelf. The bathymetry distributed the steepening and breaking process across the shelf so that the wavelength and wave height were reduced gradually as the shore was approached. The wave height 5 km from shore was about 4 in.
The sea surface directional wave spectrum was measured for the first time in all quadrants of a hurricane in open water using the NASA scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane research aircraft at 1.5 kilometer height. The SRA measures the energetic portion of the directional wave spectrum by generating a topographic map of the sea surface. The data were acquired on 24 August 1998 when Hurricane Bonnie was 400 km east of Abaco Island, Bahamas. Individual waves with heights up to 19 meters were observed and the spatial variation of the wave field was dramatic. The dominant waves generally propagated at significant angles to the downwind direction. At one position, three different wave systems of comparable energy and wavelength crossed each other. The aircraft spent over five hours within 180 kilometers of the Hurricane Bonnie eye and made five eye penetrations. On 26 August 1998, the SRA at 2.2 kilometer height documented the directional wave spectrum in the region between Charleston, SC, and Cape Hatteras, NC, as Hurricane Bonnie was making landfall near Wilmington, NC. The storm was similar in size during the two flights, but the maximum speed in the NOAA Hurricane Research Division surface wind analysis was 15% lower prior to landfall (39 meters per second) than it had been in the open ocean (46 meters per second). This was compensated for by its faster movement prior to landfall (9.5 meters per second) than when it was encountered in the open ocean (5 meters per second), significantly increasing the effective fetch and duration of waves near the peak of the spectrum which propagated in the direction of the storm track. The open ocean wave height variation indicated that Hurricane Bonnie would have produced waves of 11 meters significant wave height on the shore northeast of Wilmington had it not been for the continental shelf. The bathymetry distributed the steepening and breaking process across the shelf so that the wavelength and wave height were reduced gradually as the shore was approached. The wave height 5 kilometers from shore was about 4 meters.
This viewgraph presentation gives an overview of the ground test of the urine processing assembly for accelerations and transfer functions. Details are given on the test setup, test data, data analysis, analytical results, and microgravity assessment. The conclusions of the tests include the following: (1) the single input/multiple output method is useful if the data is acquired by tri-axial accelerometers and inputs can be considered uncorrelated; (2) tying coherence with the matrix yields higher confidence in results; (3) the WRS#2 rack ORUs need to be isolated; (4) and future work includes a plan for characterizing performance of isolation materials.
This viewgraph presentation provides an overview of the proposed Momentum-eXchange/Electrodynamic Reboost (MXER) space hardware system. The tether system would be position cart-wheeling cables above the Earth and then, rotating like a giant sling, would capture spacecraft or payloads from space shuttles in low Earth orbits and launch them into higher orbits. This study focuses on system validation and structural design issues for MXER. Topics examined include: tether facility design, ED tether system, payload capture/catch mechanism, payload accomodations assembly (PAA), PAA rendezvous capability, and PAA capability to correct tether misthrows.
The value of the International Space Station (ISS) as a premier microgravity environment is currently at risk due to structure-borne vibration. The vibration sources are varied and include crew activities such as exercising or simply moving from module to module, and electro- mechanical equipment such as fans and pumps. Given such potential degradation of usable microgravity, anything that can be done to dampen vibration on-orbit will significantly benefit microgravity users. Most vibration isolation schemes, both active and passive, have proven to be expensive - both operationally and from the cost of integrating isolation systems into primary/secondary structural interfaces (e.g., the ISS module/rack interface). Recently, passively absorptive materials have been tested at the bolt interfaces between the operating equipment and support structure (secondary/tertiary structural interfaces). The results indicate that these materials may prove cost-effective in mitigating the vibrational problems of the ISS. We report herein tests of passive absorbers placed at the interface of a vibration-inducing component: the Development Distillation Assembly, a subassembly of the Urine Processing Assembly, which is a rotating centrifuge and cylinder assembly attached to a mounting plate. Passive isolators were installed between this mounting plate and its support shelf. Three materials were tested: BISCO HT-800, Sorbothane 30 and Sorbothane 50, plus a control test with a hard shim. In addition, four distinct combinations of the HT-800 and Sorbothane 50 were tested. Results show a significant (three orders of magnitude) reduction of transmitted energy, as measured in power spectral density (PSD), using the isolation materials. It is noted, however, that passive materials cannot prevent the transmission of very strong forces or absorb the total energy induced from structural resonances.
Operation Everest II was designed to examine the physiological responses to gradual decompression simulating an ascent of Mt Everest (8,848 m) to an inspired PO2 of 43 mmHg. The principal studies conducted were cardiovascular, respiratory, muscular-skeletal and metabolic responses to exercise. Eight healthy males aged 21-31 years began the "ascent" and six successfully reached the "summit", where their resting arterial blood gases were PO2 = 30 mmHg and PCO2 = 11 mmHg, pH = 7.56. Their maximal oxygen uptake decreased from 3.98 +/- 0.2 L/min at sea level to 1.17 +/- 0.08 L/min at PIO2 43 mmHg. The principal factors responsible for oxygen transport from the atmosphere to tissues were (1) Alveolar ventilation--a four fold increase. (2) Diffusion from the alveolus to end capillary blood--unchanged. (3) Cardiac function (assessed by hemodynamics, echocardiography and electrocardiography)--normal--although maximum cardiac output and heart rate were reduced. (4) Oxygen extraction--maximal with PvO2 14.8 +/- 1 mmHg. With increasing altitude maximal blood and muscle lactate progressively declined although at any submaximal intensity blood and muscle lactate was higher at higher altitudes.